Ryanair is shutting its base at Frankfurt Hahn airport after German pilots voted to reject pay cuts.
The firm said in a memo to pilots that its bases at Berlin Tegel and Dusseldorf airports were also at risk of closure by the end of the summer.
Airlines have been struggling because of global travel restrictions aimed at halting the spread of the coronavirus.
Ryanair’s UK pilots and cabin crew recently voted to accept pay cuts to reduce job losses.
“We must move on with alternative measures to deliver savings, which regrettably will mean base closures and dismissals,” Ryanair said in a memo to its German pilots.
Ryanair announced in May it was set to cut 3,000 jobs across Europe.
However, earlier this month, the company revealed that it had cut a deal with the Unite union so that UK cabin crew jobs would be safeguarded.